scholarly journals Chaotic and Hyperchaotic Self-Oscillations of Lambda Diode Composed by Generalized Bipolar Transistors

2021 ◽  
Vol 11 (8) ◽  
pp. 3326
Author(s):  
Jiri Petrzela
Keyword(s):  
Mathematical Modeling ◽  
Simple Structure ◽  
Bipolar Transistors ◽  
Time Sequence ◽  
Flow Quantification ◽  
Chaotic Attractors ◽  
Chaotic Oscillator ◽  
Admittance Matrix ◽  
Long Time ◽  
Dynamical Flow

This paper is focused on the investigation of self-oscillation regimes associated with very simple structure of lambda diode. This building block is constructed by using coupled generalized bipolar transistors. In the stage of mathematical modeling, each transistor is considered as two-port described by full admittance matrix with scalar polynomial forward trans-conductance and linear backward trans-conductance. Thorough numerical analysis including routines of dynamical flow quantification indicate the existence of self-excited dense strange attractors. Plots showing first two Lyapunov exponents as functions of adjustable parameters, signal entropy calculated from generated time sequence, sensitivity analysis, and other results are provided in this paper. By the construction of a flow-equivalent chaotic oscillator, robustness and long-time geometrical stability of the generated chaotic attractors is documented by the experimental measurement, namely by showing captured oscilloscope screenshots.

scholarly journals DESIGN OF TIME DELAYED CHAOTIC CIRCUIT WITH THRESHOLD CONTROLLER

2011 ◽  
Vol 21 (03) ◽  
pp. 725-735 ◽  
Author(s):  
K. SRINIVASAN ◽  
I. RAJA MOHAMED ◽  
K. MURALI ◽  
M. LAKSHMANAN ◽  
SUDESHNA SINHA
Keyword(s):  
Numerical Simulations ◽  
Linear Function ◽  
Piecewise Linear ◽  
Piecewise Linear Function ◽  
Operational Amplifiers ◽  
Phase Portraits ◽  
Chaotic Attractors ◽  
Chaotic Oscillator ◽  
Threshold Values ◽  
Chaotic Circuit

A novel time delayed chaotic oscillator exhibiting mono- and double scroll complex chaotic attractors is designed. This circuit consists of only a few operational amplifiers and diodes and employs a threshold controller for flexibility. It efficiently implements a piecewise linear function. The control of piecewise linear function facilitates controlling the shape of the attractors. This is demonstrated by constructing the phase portraits of the attractors through numerical simulations and hardware experiments. Based on these studies, we find that this circuit can produce multi-scroll chaotic attractors by just introducing more number of threshold values.

scholarly journals PVT-Robust CMOS Programmable Chaotic Oscillator: Synchronization of Two 7-Scroll Attractors

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 252 ◽  
Author(s):  
Victor Carbajal-Gomez ◽  
Esteban Tlelo-Cuautle ◽  
Carlos Sanchez-Lopez ◽  
Francisco Fernandez-Fernandez
Keyword(s):  
Integrated Circuit ◽  
Secure Communication ◽  
Piecewise Linear ◽  
Cmos Technology ◽  
Oxide Semiconductor ◽  
Chaotic Attractors ◽  
Chaotic Oscillator ◽  
Maximum Lyapunov Exponent ◽  
Chaotic Oscillators ◽  
Cmos Integrated Circuit

Designing chaotic oscillators using complementary metal-oxide-semiconductor (CMOS) integrated circuit technology for generating multi-scroll attractors has been a challenge. That way, we introduce a current-mode piecewise-linear (PWL) function based on CMOS cells that allow programmable generation of 2–7-scroll chaotic attractors. The mathematical model of the chaotic oscillator designed herein has four coefficients and a PWL function, which can be varied to provide a high value of the maximum Lyapunov exponent. The coefficients are implemented electronically by designing operational transconductance amplifiers that allow programmability of their transconductances. Design simulations of the chaotic oscillator are provided for the 0.35 μ m CMOS technology. Post-layout and process–voltage–temperature (PVT) variation simulations demonstrate robustness of the multi-scroll chaotic attractors. Finally, we highlight the synchronization of two seven-scroll attractors in a master–slave topology by generalized Hamiltonian forms and observer approach. Simulation results show that the synchronized CMOS chaotic oscillators are robust to PVT variations and are suitable for chaotic secure communication applications.

scholarly journals Colpitts Chaotic Oscillator Coupling with a Generalized Memristor

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Lu ◽  
Changdi Li ◽  
Zicheng Zhao ◽  
Bocheng Bao ◽  
Quan Xu
Keyword(s):  
Mathematical Model ◽  
Equilibrium Point ◽  
Fourth Order ◽  
Chaotic Attractors ◽  
Chaotic Oscillator ◽  
Nonlinear Phenomena ◽  
Unique Equilibrium ◽  
First Order ◽  
The Mathematical Model ◽  
Order Parallel

By introducing a generalized memristor into a fourth-order Colpitts chaotic oscillator, a new memristive Colpitts chaotic oscillator is proposed in this paper. The generalized memristor is equivalent to a diode bridge cascaded with a first-order parallel RC filter. Chaotic attractors of the oscillator are numerically revealed from the mathematical model and experimentally captured from the physical circuit. The dynamics of the memristive Colpitts chaotic oscillator is investigated both theoretically and numerically, from which it can be found that the oscillator has a unique equilibrium point and displays complex nonlinear phenomena.

scholarly journals A Review Predictive Mathematical Modeling of Alkali-Silica Reaction in Concrete: evolution, current understanding and the knowledge gaps

2021 ◽  
Vol 10 (11) ◽  
pp. e449101119810
Author(s):  
Dhiego Henrique Ferreira Revoredo ◽  
Ana Cecília Vieira Nobrega ◽  
Arnaldo Manoel Pereira Carneiro ◽  
João Emanuell Araújo Marciano
Keyword(s):  
Mathematical Modeling ◽  
Literature Review ◽  
Mathematical Models ◽  
State Of The Art ◽  
Meta Analysis ◽  
Methodological Approach ◽  
Phenomenological Approach ◽  
Alkali Silica Reaction ◽  
Long Time ◽  
Concrete Degradation

Predictive mathematical models have been proposed in alkali-silica reaction (ASR). Predicting concrete degradation and its effects on mechanical properties is of interest given the long time until degradation becomes critical for intervention and recovery, and difficult structural access for predictive and corrective monitoring and treatment. The present paper presents a general overview of the evolution of the aforementioned predictive mathematical models, interrelating them to the maturation of the phenomenological state of the art associated with ASR.  For this purpose, a systematic literature review was used, followed by bibliometric analysis and meta-analysis. In this study, 104 articles from 1974 to 2020 were selected, of which 31 articles were reviewed on the topic of mathematical modeling of ASR. The results of the method indicated the importance of the methodological approach of literature review to provide a comprehensive and chronological view of the evolution of ASR consolidated in the literature. It was found that the mathematical models have evolved considering the phenomenological approach of ASR.

scholarly journals Mathematical Modelling and Simulation of Band Pass Filters using the Floating Admittance Matrix Method

2021 ◽  
Vol 20 ◽  
pp. 208-214
Author(s):  
Sanjay Kumar Roy ◽  
Kamal Kumar Sharma ◽  
Cherry Bhargava ◽  
Brahmadeo Prasad Singh
Keyword(s):  
Mathematical Modeling ◽  
Matrix Method ◽  
Transfer Functions ◽  
Large Network ◽  
Admittance Matrix ◽  
The Matrix ◽  
Band Pass ◽  
Time And Energy ◽  
Mathematical Modelling And Simulation ◽  
Partitioning Technique

This article aims to develop a band pass filter's mathematical model using the Floating Admittance Matrix (FAM) method. The use of the conventional methods of analysis based KCL, KVL, Thevenin's, Norton's depends on the type of the particular circuit. The proposed mathematical modeling using the floating admittance matrix method is unique, and the same can be used for all types of circuits. This method uses the partitioning technique for large network. The sum property of all the elements of any row or any column equal to zero provides the assurance to proceed further for analysis or re-observe the very first equation. This saves time and energy. The FAM method presented here is so simple that anybody with slight knowledge of electronics but understating the matrix maneuvering, can analyze any circuit to derive all types of transfer functions. The mathematical modeling using the FAM method provides leverage to the designer to comfortably adjust their design at any stage of analysis. These statements provide compelling reasons for the adoption of the proposed process and demonstrate its benefits

The Reconfigurable Innovation of Reciprocating Rectilinear Moving Mechanism at High Frequency with Low Load Driven by Two Symmetrical Eccentric Cams

2009 ◽  
Vol 628-629 ◽  
pp. 125-130 ◽  
Author(s):  
Ming Di Wang ◽  
Kang Min Zhong ◽  
Zheng Chen
Keyword(s):  
Friction Force ◽  
High Frequency ◽  
Simple Structure ◽  
Good Property ◽  
Guide Rail ◽  
Reconfigurable Devices ◽  
Low Load ◽  
Long Time ◽  
Practical Engineering ◽  
Crank Mechanism

In many occasions of the practical engineering, the reciprocating rectilinear movement at high frequency is appeared commonly, which is usually completed by the slider-crank mechanism. But there has big friction force between the guide rail and the block, thus the big friction loss can be caused. So when working in a long time, the mechanism will be heated and distorted. And a big torque will be caused in the guide rail, the oscillation will be generated when move at high frequency. In order to overcome these defections, the reciprocating rectilinear moving mechanism at high frequency with low load driven by two symmetrical eccentric cams is innovated. And to realize the different travel in economical way, the rapid reconfigurable devices based on this mechanisum are innovated too. These innovated mechanism is quite symmetrical, so the friction force between the guide rail and the leader can be almost ignored and the oscillation is very small too. Then, the mechanical and movement property are analyzed and compared with the slider-crank mechanism, which proves that these mechanism have simple structure and good property. Through the analysis of the travel, the merit of strong adaptability is found out. Furthermore, the components in these devices can be reused in different occasions, so the reconfigurable thinking provides one economical method for big production rapidly.

scholarly journals Mathematical Modelling and Simulation of Band Pass Filters Using The Floating Admittance Matrix Method.

2021 ◽  
Author(s):  
SANJAY KUMAR ROY ◽  
Cherry Bhargava ◽  
Kamal Kumar Sharma ◽  
Brahmadeo Prasad Singh
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Modelling ◽  
Matrix Method ◽  
Circuit Analysis ◽  
Modelling And Simulation ◽  
Notch Filters ◽  
Admittance Matrix ◽  
New Strategy ◽  
Band Pass ◽  
Mathematical Modelling And Simulation

Abstract This article describes the Band Pass Filters mathematical modeling, focusing on solutions using the Floating Admittance matrix method (FAM). The solution using the FAM Method looks superior for any circuit analysis. We are introducing a new strategy resulting in one of the best designs of the Bandpass and the Notch Filters. This document provides compelling reasons for the proposed Process, demonstrates its benefits and many valuable extensions and resources.

scholarly journals Reliability Analysis of an Industrial System Under Cost-Free Warranty and System Rest Policy

2019 ◽  
Vol 49 (2) ◽  
pp. 377-395
Author(s):  
Pardeep Kumar ◽  
Amit Kumar
Keyword(s):  
Mathematical Modeling ◽  
Reliability Analysis ◽  
System Performance ◽  
Industrial System ◽  
Long Time ◽  
Specific Amount

Abstract The aim of this paper is to analyze a system, which consists of two components, working under a cost-free warranty policy. Past literature reflects that till now the focus of researchers is those systems which work without taking rest. But here authors emphasized on an industrial system which takes rest after working for a specific amount of time. This strategy helps the system to run for a long time with less failure. After taking rest, the system starts its working again. During the mathematical modeling of the system various state of the same are critically analyzed. Reliability of the considered system has been obtained for the different combinations of failure and repair rates. Also, the various parameters which affect the system performance have been evaluated.

Simulation of Heartbeat Dynamics: A Nonlinear Model

1998 ◽  
Vol 08 (08) ◽  
pp. 1725-1731 ◽  
Author(s):  
Maria G. Signorini ◽  
Diego di Bernardo
Keyword(s):  
Mathematical Modeling ◽  
Simple Structure ◽  
Nonlinear Differential Equations ◽  
Atrioventricular Node ◽  
Nonlinear Oscillators ◽  
Conduction System ◽  
Cardiac Conduction ◽  
Cardiac Conduction System ◽  
Real Situation ◽  
Cardiac Dynamics

The mathematical modeling of biological systems has proven to be a valuable tool by allowing experiments which would otherwise be unfeasible in a real situation. In this work we propose a system of nonlinear differential equations describing the macroscopic behavior of the cardiac conduction system. The model describes the interactoin between the SinoAtrial and AtrioVentricular node. Its very simple structure consists of two nonlinear oscillators resistively coupled. The numerical analysis detects different kinds of bifurcations whose pathophysiological meanings are discussed. Moreover, the model is able to classify different pathologies, such as several classes of arrhythmic events, as well as to suggest hypothesis on the mechanisms that induce them. These results also show that the mechanisms generating the heartbeat obey complex laws. The model provides a wuite complete description of different pathological phenomena and its simplicity can be exploited for further studies on the control of cardiac dynamics.

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